


Fire Emblem Three Houses Roleswap AU

by starryskiessleepynights



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Gen, M/M, Multi, Roleswap
Language: English
Status: In-Progress
Published: 2019-12-16
Updated: 2020-01-31
Packaged: 2021-02-26 00:20:11
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 3,806
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21824290
Author URL: https://archiveofourown.org/users/starryskiessleepynights/pseuds/starryskiessleepynights
Summary: A roleswap AU of three houses.
Relationships: Dimitri Alexandre Blaiddyd/Claude von Riegan, Edelgard von Hresvelg/Hubert von Vestra, Edelgard von Hresvelg/My Unit | Byleth, Ferdinand von Aegir/Hubert von Vestra
Kudos: 20





	1. Chapter 1

It was the middle of the night, and everyone had been sleeping, like most regular human beings do in the middle of the night. Then there was Byleth. Byleth had simply been trying to sleep, as she had awakened because of whatever the fuck Claude and Dimitri did every other night in their bedroom. But then there was... a pillar of light. It came out of nowhere, and then it... left. Gone. Byleth wanted to go and inform someone of this strange light, but she also wanted to go to sleep, and self-care is more important.

Byleth had been rudely awakened by a guard (who was not the angelic and godly Gatekeeper) who had wanted her to let in two travelers who wanted to live at the monastery. Since Byleth actually trusted people to come in the monastery, she decided that she'd let the people come in the monastery. She walked to the entrance of the monastery. She noticed that the two travelers had hoods on.

"Hello there~." one of the travelers said. His voice was masculine, so Byleth guessed this person was probably a male. (Or just trans.) "As you have probably heard, me and my... er, friend here would like to live in the monastery for a while."

"Really?" Byleth asked. People asking to live in the monastery who weren't soldiers was.... unusual, to say the least.

"Yeah!" The other traveler sounded strangely excited, and Byleth guessed that this traveler was a female. "I-I mean... yeah."

"We'd like a room with a closet, if that's alright.." the masculine-sounding traveler requested. 

"Hm. Alright, I'll see if there's any rooms with closets. Just follow me." Byleth started to walk around the 2nd floor dormitories, before finding a room. Which happened to have a closet. "Is this fine for you and your friend?" 

"Just perfect, darling~ Thank you."

The travelers walked through the door, and closed it.


	2. Chapter 2

**Summary for the Chapter:**

> Byleth makes a shocking discovery at the monastery's infirmary.

The next day, Byleth wanted to go check around the monastery to make sure everything was fine.

The first stop was the mess hall; Byleth was hungry, so she decided to grab a quick snack to eat. After all, self-care was super important to Byleth. She then would stop by the gardens. It was really something she enjoyed, considering she could pick the flowers from the gardens and give them to friends or people that she wanted to be friends with. Also she got to see Dedue. Dedue is cool.

Then she went to the fishing pond, grabbed a fish, and ate it raw without chewing. It was truly a delicious meal, to be honest. Everyone who was near the fishing pond could only stare in disgust as she ate the poor fish like a snake.

Then she went to the stables, where Sylvain and Lorenz were practicing their horse riding to be able to assert their dominance and get women easier. That really wouldn't work, but Byleth didn't say anything.

Then at the training grounds, Dimitri was training. I mean, considering how loud he was when fucking Claude last night, Byleth wondered how he'd even need to train at all. That was probably a workout in and of itself.

Then... she went to the infirmary. And what she saw there... was horrifying. In the animal part of the infirmary, many wyverns and Pegasi were there, with arrows in them. Blood was everywhere, basically. And it was... kinda scary how many wyverns were there... She went over to the healer.

"Hey... what happened with all of these animals?" Byleth asked.

"Wyvern riders and pegasus riders report that they were simply training to ride their animals and training to fight, and then.... this happened. Arrows came out of nowhere, and shot them to the ground. Some animals died from the fall because they were so high up."

"How could the attacker hit them from so high up?"

"Nobody knows. It could be a flier who also mastered archery, but reports are of the arrows coming from down below."

"I'm going to go to Claude and ask him to help me investigate all the archers in the monastery."

"Could you also get more healers to help? These are a lot of hurt animals. Also, fliers have reported getting axe wounds after they fall."

"I see. I'll go investigate this further. Thanks for the information."

Byleth left the infirmary and rushed to Claude's dorm room. She hoped he wasn't masturbating or something. She knocked on the door. "Claude?" She asked. "Are you in there?"

"One second." She heard, and then Claude opened the door. "What do you need?"

"So, I went to the infirmary, and--"

"Fliers and their mounts were shot and cut with an axe? Yeah, I heard."

"Oh. Well, we need to interrogate all the archers and axe users in the monastery."

"I would, but... wouldn't it be a waste of time? Most of the people in the monastery are too kind to do something like that. I mean, are you telling me Caspar would go and hurt someone like that? Or Bernadetta? Or Ignatz?"

"No, but... it's worth a shot."

**Notes for the Chapter:**

> I felt like it made sense to add an infirmary into the monastery. I mean, why would there not be one?


	3. Chapter 3

**Summary for the Chapter:**

> Byleth interrogates a few people at the monastery.

**Notes for the Chapter:**

> I forgot to mention; this is POST-TIMESKIP.

In a dark room, Byleth sat in a chair behind a table. You might ask what Byleth was doing. Well, she was waiting for a guard to bring in the first person she would interrogate; Bernadetta. Bernadetta was in her room all day, so she might've been up to something.

Eventually, the door opened, and Bernadetta awkwardly shuffled in, before taking a seat in the chair. "H-hi, professor..."

"Cut the shy shit." said Byleth. She was going for a more aggressive approach. "What the hell did you do?"

"I d-don't know what you're talking about!"

"Don't act like you haven't heard about the attack against the mounts earlier."

"Wh-what? What happened?"

"Wait. Do you NOT know what happened?"

"I don't! I don't know! I swear!"

"Well... what were you doing earlier this morning?"

"I was simply in my room, reading a nice book..."

"Oh. Well... that does sound more like you, to be honest. Alright. You're dismissed."

The next person Byleth was going to interrogate was Caspar. He didn't seem like he'd hurt anyone, but... Byleth had to be sure. Caspar burst in to the room, seeming far too excited.

"HEY PROFESSOR!"

"Jeez--- too loud."

"Why am I here again?" Caspar basically jumped into his seat.

"Uh, did you do anything earlier this morning?"

"Yup!"

"What did you do?"

"I got myself a bite to eat, then I went to the training grounds to train for a while, and then I went to my room to rest!"

"Alright. Uh, did you know anybody who was at the wyvern training grounds?"

"Oh, yeah! Hilda was probably up there flying on her wyvern. She might be in the infirmary, though..."

"Oh, yeah. I should probably ask Hilda. Can you get her for me?"

"Sure!" Caspar jumped out of his chair and ran out of the room, and about a minute later he came back with Hilda.

"Wow. That was fast. Hilda, please sit down."

Hilda had a broken wrist from the fall she took off of her wyvern. "Hey, professor..."

"Hilda, are you okay?"

"I'm fine."

"Did you see anything from before you went on the wyvern?"

"Well, I did overhear some people talking about going to the flier training grounds and 'causing something big' but I didn't investigate further."

"Do you know who these people are?"

"Unfortunately... no."

"Alright. Go to your room for now, and get some rest."


	4. Chapter 4

**Summary for the Chapter:**

> Byleth witnesses another attack.

During Byleth's daily monastery adventure, she noticed the monastery was... stranger. People were walking around less. She noticed that the flier training grounds were mostly empty. The mess hall was way more quiet than it used to be. There was nobody fishing, and nobody gardening, not even Dedue. Byleth decided that she'd go to the training grounds and try to train to relieve some stress.

However... when she went there, she ran into something horrifying. She saw the two hooded travelers from earlier, or maybe they were just people in hoods, attacking and fighting the people who were training. The attackers were laughing, and they seemed to be enjoying this. Byleth was horrified.

Byleth ran away, trying to get more people to help, but as she did, she felt a hand grab the back of her shirt.

"Now where do you think you're going, darling?" a voice behind her said.

Yup, it was definitely the travelers. God dammit. Byleth tried to turn around and stab the traveler with a sword, and she did, but the traveler didn't seem to mind.

"Hilda, keep attacking, and retreat when you might get caught." The traveler said. "I got a hostage."

"Got it!" the other traveler responded.

Hilda? Byleth was very, very confused. But Hilda was in her dorm... resting. She couldn't be the attacker; she was a victim!

The traveler carrying Byleth interrupted her thoughts and started sprinting to the dorm room, while still carrying Byleth. When they arrived at their destination, the traveler practically threw Byleth in the closet.

"Have you figured out what this closet is for?" The traveler asked.

"W-wait, no--"

"I'm sorry, but... this is essential. We can't let any witnesses get away with any information."

"But--"

And then the closet doors were closed. Great.

**Notes for the Chapter:**

> Wow, 7 kudos! That's a lot more than I expected for now. Could you guys leave comments too? (I hope I'm not asking for too much)


	5. Chapter 5

**Summary for the Chapter:**

> Byleth eavesdrops while she's trapped in the closet.

Byleth had been in the closet for a while. It was pretty scary, to be honest. I mean, it was a small space. Byleth didn't even know how she was humanly fitting in there. Byleth decided that she would try to hear the two travelers' conversations if she was really gonna be stuck in there.

"Claude, are you alright? That woman stabbed you." A feminine voice spoke. Claude? That couldn't be right. Claude's dormitory wasn't here, and Byleth didn't stab Claude. Claude would never even do anything harmful like that.

"I'm fine, Hilda. Don't stress yourself out about it. It's just a small wound." said 'Claude'. Now that Byleth listened closely... the person did sound a lot like Claude.

"You got stabbed. With a sword. How is it a 'small wound'."

"Hilda, you do realize I have regenerative powers, right?" 

"Oh, yeah. Forgot."

"Anyway, we need to plan out our next attack on this monastery."

"Hell yeah! This'll be so much fun!"

"Don't get too excited, Hilda. We'll have to study more on how many people are at the monastery at certain times." 

"Aw. Can't we just kill people?"

"No, Hilda. That would be inefficient, and would probably lead to us getting caught."

"Can we kill our hostage?"

Byleth did not want to be killed, personally. She was defenseless. Thankfully, she hadn't brought her Sword of the Creator and instead brought a different sword, so they didn't have that.

"No. We can't kill our hostage yet. We might kill her eventually, though."

"...Ah. Can I... kill... um..."

"No. You're not killing anyone until we plan this out." Claude said. "Hilda, could you go and collect some data on which people are out on certain times?"

"But aren't they looking for a hooded figure?"

"You look like Hilda. You'll pass just fine, if you're a good enough actor."

"Alright." 

Byleth heard a door opening and closing, and then the closet doors opened. Byleth took a breath of fresh air for once. "Finally, you're letting me out. I got a horrible back ache..." Byleth stretched. So it really was Claude... unless it was a very good makeup artist. This person--- Claude, looked very similar to the Claude that Byleth knew, except he had red eyeliner.

"I'm not letting you out, darling. I'm just not a horrible person, so I've decided to do this instead of keeping you in a closet." Claude tied Byleth's hands to a bedpost. "There. Now you can't escape."

"You're skilled with ropes. Do you do this kind of stuff to Dimitri?"

"I don't like to talk about that." There was awkward silence in the room, but Claude then broke it. "Anyway, I've had fun talking to you, but I really need to join Hilda in collecting data." Claude put on a hood. "Goodbye~!" Claude left the room, leaving Byleth alone to think about things.


	6. Chapter 6

**Summary for the Chapter:**

> Byleth escapes Claude's room.

When Claude (who will now be referred to as alt!claude) left, Byleth decided that she was going to try to escape this room. The problem was... how would she? These people were good kidnappers. There was nothing in sight around that could possibly help her escape. But... maybe...

Byleth tried to reach into her shirt, hoping she could reach what she was looking for for even though her wrists were tied. "Come on... come on... Got it!" She could feel her backup knife at the tip of her fingertips. Somehow, they might've forgotten to check her for secret weapons.

She tried grabbing at the knife, and eventually she got it. Now, it was time to cut at the ropes. She started by cutting at the rope at her right hand, and eventually, after a while of just slicing and cutting at it, it came loose. Then she worked at cutting the other one, doing it a bit faster considering that her wrists were free. 

And then she stood up, looking at her wrists. There were small bruises, but aside from that it was nothing bad. Byleth basically sprinted out of the room. Problem is, she forgot to open the door, so her face kinda just slammed into the door. Ouch. It wasn't too much of a problem, though, and so she started to open the door and R U N. She ran as far as she possibly could. 

Byleth ran to her room, and quickly grabbed the Sword of the Creator. She figured Alt!Claude would be interested in it. Then she sprinted over to Claude and Dimitri's room and practically banged on the door.

"Um, one second---" she heard Dimitri yell.

"This is urgent. I need to come in now."

The door opened. "What do you need?" Dimitri asked.

"Just let me in." Byleth practically burst through the door. 

Dimitri raised an eyebrow. "Are you okay?"

"I'll explain after. Just lock the door, don't let anybody in. Even if it sounds like Claude. No, especially if it sounds like Claude."


	7. Chapter 7

**Summary for the Chapter:**

> Byleth informs Dimitri and Claude of the kidnapping.

Byleth felt a bit dizzy, and like she was about to vomit. She was... very nervous. She knew she had to tell Dimitri, everything, and fast. 

"Byleth... are you sick? Do you need to go to the, uh, infirmary or like..." Dimitri raised an eyebrow.

"I'm fine... it's just... you wouldn't BELIEVE what just happened to me."

"I mean, you did go missing for a while... people just assumed you were out training or something."

"Well... I was kidnapped."

"Kidnapped? By who?"

"The travelers that came in a couple of days ago."

"You mean those hooded people?"

"Yeah. And they happened to be, like, some weird people who look like Claude and Hilda."

"They're probably shapeshifters. We should investigate more."

"They didn't seem like shapeshifters though. If they were, they'd probably shift back to their original forms once in a while. And... the people had small differences to the Claude and Hilda we know. If they were shapeshifters... wouldn't they try to look the exact same?"

"You may be right. Well... is. there anything else you've found out?"

"They've been doing the attacks at the training grounds. The person who looked like Claude said they were going to collect data around the monastery to figure out the exact next area they could strike at."

"I'm going to investigate this. You should probably stay in this room for now."

"You don't want me to come with you?"

"It would be more dangerous for you. Since these people have kidnapped you, they know that you know their plans. You should probably stay here."

"Alright... Stay safe, Dimitri."

Dimitri nodded, and left the room.

Byleth decided to look around the room, and immediately she saw a box. Said box was labeled "Nudes" She was not looking at that. Was she? Fuck it. She tiptoed over to the box and opened it. Inside was a piece of paper. Said paper said "lol get fucked nosy ass pervert bitch. why would i even put my nudes box out in the open? lmao what a clown." Yeah this was Claude's work. Like, the real Claude. Probably. Byleth hoped so.

Byleth heard a knock on the door. "Dimitri? Are you in there?" She heard a voice. It was Claude. Byleth thought for a second. How could she identify if this was the real Claude?

"Um... sorry, Claude, but Dimitri's not here. And also... uh... you can't really come in right now."

"Why not? Also, Professor, why are you in my room?"

"...Uh... I'd explain, but you might not be the real Claude."

"...What do you mean? There's only one Claude. And it's me."

Byleth thought for a second. "Hold on." She cracked the door open, like, an inch, and looked. "...Oh. It is you!" Byleth let out a sigh of relief. "Come on in."

Claude walked into the room. "So why didn't you let me in?"

Byleth explained what happened hesitantly. 

"...And you're telling me Dimitri went off by himself to go and investigate this?"

"Yeah."

Claude sighed. "Dimitri is really dumb sometimes." And then he sprinted out the room, leaving Byleth alone.


	8. Chapter 8

**Summary for the Chapter:**

> A chapter from Alt!Claude's perspective.

Alt!Claude was not having a very good time, and neither was his partner, Alt!Hilda. Alt!Claude had been sent through a huge portal thing, in the middle of the goddamn night, with Alt!Hilda and Alt!Lysithea. Because Alt!Claude was an asshole, he left Alt!Lysithea there and went to the monastery with Alt!Hilda. 

Currently, Alt!Claude was collecting data on this stupid ass monastery. His goal when coming here was to find his sworn enemy, Alt!Edelgard, who was the leader of the Kingdom, but he quickly realized this world was unlike his own in many different ways. He split the duty of collecting data with Alt!Hilda, who was collecting data on the other side of the monastery.

Alt!Claude was simply walking and collecting data, when he bumped into... this world's Dimitri, apparently. I mean, who could look that much like Dimitri? 

Suddenly, Dimitri grabbed him by the shirt. "Who are you, and why are you in the--"

"Get your fucking hands off me." Alt!Claude punched Dimitri in the face. Said action... actually gave him a black eye. Wow. "...Or do you like that, because of your weird hand kink?" 

Dimitri got up, and in response, Alt!Claude picked Dimitri up and threw him. "Don't even try." said Alt!Claude, before walking away. But as he did... he felt a sharp pain in his back. "Eh?" Alt!Claude looked behind him to see... himself. Jeez, this was weird. Must be the Claude of this world. "...That doesn't even hurt." Said Alt!Claude, pulling the arrow out of his back and continuing to walk. In a couple of seconds, the wound was basically gone.

"What the fuck?" Said Claude. "That arrow should've done significant damage to you."

"And it didn't. Now shut the fuck up and leave me the fuck alone." said Alt!Claude. 

Claude crossed his arms. "Are you... me?"

"Why would I be?"

"Byleth told me that people who looked like me and Hilda were roaming around and doing bad shit."

"Byleth escaped?"

"And that just confirmed what she said."

"You know what? There's no use of staying here. Bye." Alt!Claude sprinted away. He ran to the side of the monastery Alt!Hilda was at, and spotted her "Hilda!"

Alt!Hilda was writing down some things. "Yes?"

"We have to go now." Alt!Claude grabbed Alt!Hilda and ran to the room that was given to them, slammed the door shut, locked it, and barricaded it with cabinets and other things.

"...What's this for?" Alt!Hilda asked. 

"Byleth escaped, and told others about this. This barricade will make it harder for them to get in while we prepare."

"Why are we staying here? We should be escaping!"

"Well we can't leave this shitty monastery without a final attack. We're gonna go and try to hurt as many people as possible."

"That sounds brutal." Alt!Hilda paused. Alt!Claude was confused for a moment, considering that Alt!Hilda normally loved brutal stuff. "I love it! When are we doing it?" 

"Not sure. But first... we have to get ready. And fast. Our barricade is... er, not the best."


	9. Chapter 9

**Summary for the Chapter:**

> From Alt!Edelgard's perspective.

A couple of days earlier...

Alt!Edelgard woke up on the ground. Her immediate instinct was to jump up and look around. "...Where the fuck am I?" She asked herself. The last thing she remembered was planning something, and then some beam of light enveloped her and... now she was here. When looking around, she saw Alt!Hubert and Alt!Ferdinand laying on the ground. "Well... okay." She decided to pick Alt!Hubert up, when she heard a wyvern.

It could be Alt!Claude. Well, fuck that bitch. What a dickhead. Literal asshole. Fuck that guy. Fucker. Little shit ass bitch. Alt!Edelgard decided that she would simply insult him to his face instead of thinking about it in her head. Alt!Edelgard looked up and saw a white wyvern in the sky. Yeah. It was that bitch. Well, Alt!Edelgard's 2 braincells had an argument for a second and then she decided against following him.

Instead... she would simply go to Adrestia. Why? Well, her reasoning was that she knew Adrestia really well... because it... at least, used to be her kingdom. Before it was overtaken by Dickhead the fourth, aka Alt!Claude, aka a plague to this fucking world.

It would take a while to walk there, though, considering she had no idea where she was---

"Edelgard, can you please drop me? You know randomly waking up in your arms brings up bad memories." She heard Alt!Hubert say, from beneath her.

"Oh yeah. Sure." Alt!Edelgard dropped him. On the ground.

"...When I said drop me, I didn't mean---"

"It doesn't matter. Let's go to Adrestia."

"You're leaving Ferdinand here?"

"Yeah..."

"You're leaving Ferdinand. Like, you're just gonna leave my boyfriend here."

"Yeah."

"Well... can't stop you. Anyway... what direction is Adrestia in?"

"I have absolutely no idea."

"You are really fucking dumb sometimes."

"I would be upset at you for that, but I have to admit... it's true. I'm a dumbass."

"Okay. Well..." Alt!Hubert paused. "If only we had, like, a wyvern or something. Would be so much easier to just... fly up."

"Can't you fly with like, magic?"

"I could, but... not that high."

"Just do it."

"Alright..." Alt!Hubert cast a spell, and then... up he went. Eventually, he came back down. "We're near the monastery. so Adrestia is... west?"

"I think. Which way is west?" 

"No idea. Let's just... uh... go this way." And they started walking.


End file.
